The invention relates to optoelectronic device-optical fiber installation and alignment.
Fiber optics is a branch of physics based on the transmission of light through transparent fibers. Individual or bundled optical fibers can carry light for hundreds of miles. An optical fiber has a highly transparent core, typically constructed from glass or plastic and encased in a cladding. Light from a laser, incandescent light bulb or other source enters one end of the optical fiber. Light traveling through the core is contained by the cladding because the inside surface of the cladding bends or reflects light inwardly. At the other end of the fiber, a detector, such as a photosensitive device or the human eye, receives the light.
Commercially available high-tolerance fiber ferrules closely received in corresponding sleeves, commonly referred to as fiber connectors, often are used to couple serial individual fibers. These ferrules, normally made of Zirconia, Alumina or metals, each are made with a through-hole for receiving a fiber. The ferrules are precisely manufactured to provide less than 1 micron center-to-center tolerance between serially-aligned ferrules. When retained in a sleeve, the ferrules maintain the cores of the fibers with high-precision alignment, which results in less than 0.5 dB coupling loss.
Many optical applications rely on interposing optoelectronic devices between aligned fibers. These optoelectronic devices often require electrical energy in order to operate. Where the fibers are coupled with fiber connectors, placement of the optoelectronic device for optimal transmission therethrough is problematic. Delivering electrical energy to or monitoring electrical signals from the optoelectronic device also is difficult.
What is needed is a fiber connector that facilitates alignment of and electrical communication with optoelectronic devices on or between optical fibers.
The invention provides for alignment of and electrical communication with optoelectronic devices on or between optical fibers. In addition to inter-fiber submicron alignment accuracy, the invention provides low-cost packaging and electrical connectivity for optoelectronic devices and detectors.
Packaging in-line devices, such as CoreTek""s tunable filter and variable optical attenuator, is disclosed. The packaging takes advantage of commercially available high tolerance fiber ferrules and corresponding sleeves normally used for fiber connectors. These ferrules, normally made of Zirconia, Alumina or metals, each are made with a through-hole for receiving a fiber. The ferrules are precisely manufactured to within less than 1 micron center-to-center tolerance between ferrules. When placed inside a sleeve, the ferrules maintain the cores of the fibers with high-precision alignment, which results in less than 0.5 dB coupling loss.
An embodiment constructed according to principles of the invention includes a ferrule configured to receive an optical fiber. An optoelectronic device is mounted on one end of the ferrule, for alignment with the fiber. Electrically-conductive deposits along the side of the ferrule supply electrical energy to or conduct electrical signals from the optoelectronic device. The optoelectronic device-carrying ferrule is inserted in a ceramic sleeve. Another ferrule, maintaining another optical fiber, also is inserted in the ceramic sleeve. The two ferrules are aligned in the sleeve and capable of transmitting light with minimal coupling loss.
Another embodiment constructed according to principles of the invention includes a second optoelectronic device mounted on the second ferrule. Electrically-conductive deposits on the second ferrule provide for electrical communication with and permit ready interposition of optoelectronic devices, such as a variable attenuator or VCSEL laser emitter, between the optical fibers maintained by the ferrules in the sleeve.
These and other features of the invention will be appreciated more readily in view of the drawings and detailed description below.